Low side AC port cap

[JJHstang]

My low side Ac port cap was missing on my Vintage Air system and that a small piece of treads was still inside and believe that was causing my AC loss of pressure. Got it removed and added 12oz of R134a. I now have cold air.
My problem is finding a new Low Side cap. I have tried 2 (1 from Auto Zone and 1 from O’riely’s and they don’t fit. I have talked to Vintage Air help and they want $12 to ship a $3 cap from San Antonio, TX to Fort Worth.
Any ideas, I am going to try Napa auto parts next.
I have attached a picture of my compressor and port locations.

 

[85GTStangGuy]

Would one of these work? (Although you'll probably still run into a shipping cost issue.)

A/C Charging Cap and Valve Kit for 1981-04 Mustang (R12 or R134) - #M-19D702-2CVK - National Parts Depot

Buy part #M-19D702-2CVK A/C Charging Cap and Valve Kit for 1981-04 Mustang (R12 or R134) for your classic vehicle from National Parts Depot. Free shipping on orders over $300, fast delivery & everyday low pricing! Order now!

www.npdlink.com

 

[Mustang5L5]

Dorman has these and most auto parts stores will stock it. Nothing special about it since these caps are standardized so if you head to NAPA they should have one. Would be no different than modern R134a AC system caps.

And yes, the caps are designed to be a sealing cap as the valves and such in these A/C fittings do leak a little. The cap creates a final seal so ensure the O-rings are in good shape and not dried out. I also use a little bit of Nylog to help with the sealing